<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar
      class="app-nav-bar"
      title="文章详情"
      left-arrow
      @click-left="$router.back()"
    />

    <div class="article-wrap">
      <h1 class="title">{{ article.title }}</h1>
      <van-cell center class="user-info">
        <div slot="title" class="name">
          {{ article.aut_name }}
        </div>
        <van-image
          class="avatar"
          slot="icon"
          round
          fit="cover"
          :src="article.aut_photo"
        />
        <div slot="label" class="pubdate">
          {{ article.pubdate | relativeTime }}
        </div>
        <van-button
          class="follow-btn"
          :type="article.is_followed ? 'default' : 'info'"
          :icon="article.is_followed?'':'plus'"
          round
          size="small"
          :loading="isFollowLoading"
          @click="onFollow"
        >
          {{ article.is_followed ? "已关注" : "关注" }}
        </van-button>
      </van-cell>
      <div
        class="markdown-body"
        v-html="article.content"
        ref="article-content"
      ></div>

      <!-- 文章评论列表 -->
      <comment-list
        :source="articleId"
        :list="commentList"
        @update-total-count="totalCommentCount = $event"
        @reply-click="onReplyClick"
      >
      </comment-list>
    </div>

    <!-- 底部区域 -->
    <div class="article-bottom">
      <van-button
        class="comment-btn"
        type="default"
        round
        size="small"
        @click="isPostShow = true"
      >
        写评论
      </van-button>

      <van-icon
        name="comment-o"
        :badge="totalCommentCount"
        color="#777"
      ></van-icon>

      <van-icon
        :color="article.is_collected ? 'orange' : '#777'"
        :name="article.is_collected ? 'star' : 'star-o'"
        @click="onCollect"
      ></van-icon>

      <van-icon
        :color="article.attitude === 1 ? 'hotpink' : '#777'"
        :name="article.attitude === 1 ? 'good-job' : 'good-job-o'"
        @click="onLike"
      >
      </van-icon>

      <van-icon name="share" color="#777777"></van-icon>
    </div>

    <!-- 发布评论 -->
    <van-popup v-model="isPostShow" position="bottom">
      <post-comment
        :target="articleId"
        @post-success="onPostSuccess"
      ></post-comment>
    </van-popup>

    <!-- 评论回复 -->
    <van-popup v-model="isReplyShow" position="bottom">
      <!-- 这里使用v-if的目的是让组件随着弹出层的显示进行渲染和销毁，防止加载过的组件不重新渲染导致数据不会重新加载的问题 -->
      <comment-reply
        v-if="isReplyShow"
        :comment="replyComment"
        :article-id="articleId"
        @close="isReplyShow = false"
      >
      </comment-reply>
    </van-popup>
  </div>
</template>

<script>
import "./github-markdown.css";
import {
  getArticleById,
  addCollect,
  deleteCollect,
  addLike,
  deleteLike,
} from "@/api/article";
import { ImagePreview } from "vant";
import { addFollow, deleteFollow } from "@/api/user";
import CommentList from "./components/comment-list";
import PostComment from "./components/post-comment.vue";
import CommentReply from "./components/comment-reply.vue";

//在组件中获取动态路由参数：
//  方式一：this.$route.params.xxx
//  方式二：props传参，推荐使用
export default {
  // 组件名称
  name: "ArticleIndex",
  // 组件参数 接收来自父组件的数据
  props: {
    articleId: {
      type: [String, Number, Object],
      required: true,
    },
  },
  // 局部注册的组件
  components: {
    CommentList,
    PostComment,
    CommentReply,
  },
  // 组件状态值
  data() {
    return {
      article: {}, //文章数据对象
      isFollowLoading: false, //关注用户按钮的loading
      /* isCollectLoading: false //收藏文章按钮的loading */
      isPostShow: false, //控制发布评论的显示状态
      commentList: [], //文章评论列表
      totalCommentCount: 0, //评论总数量
      isReplyShow: false, //控制回复的显示状态
      replyComment: {}, //当前回复评论对象
    };
  },
  // 计算属性
  computed: {},
  // 侦听器
  watch: {},
  created() {
    this.loadArticle();
  },
  mounted() {},
  // 组件方法
  methods: {
    async loadArticle() {
      const { data } = await getArticleById(this.articleId);
      this.article = data.data;
      //数据改变影响视图更新（DOM数据）不是立即的，想要立即，需要把代码放到 $nextTick 中
      //得到所有的img标签
      //this.$nextTick是Vue中提供的一个方法
      this.$nextTick(() => {
        this.handlePerviewImage();
      });

      //循环img列表，给img注册点击事件
      //在事件处理函数中调用 ImagePreview()预览
    },
    //处理预览图片
    handlePerviewImage() {
      //1.获取文章DOM容器
      const articleContent = this.$refs["article-content"];

      //2.得到所有的 img 标签
      const imgs = articleContent.querySelectorAll("img");

      //3.循环img列表，给img注册点击事件
      const imgPaths = []; //收集所有的图片路径
      imgs.forEach((img, index) => {
        imgPaths.push(img.src);
        img.onclick = function () {
          //4.在事件处理函数中调用 ImagePreview()预览
          ImagePreview({
            images: imgPaths, //预览图片路径列表
            startPosition: index, //预览图片起始位置
          });
        };
      });
    },
    //关注、取消关注
    async onFollow() {
      this.isFollowLoading = true;
      if (this.article.is_followed) {
        //已关注，取消关注
        await deleteFollow(this.article.aut_id);
      } else {
        //未关注，点击关注
        await addFollow(this.article.aut_id);
      }
      //更新视图
      this.article.is_followed = !this.article.is_followed;
      this.isFollowLoading = false;
    },
    //收藏、取消收藏
    async onCollect() {
      this.$toast.loading({
        message: "操作中...",
        forbidClick: true, //禁止背景点击
      });
      // this.isCollectLoading = true
      if (this.article.is_collected) {
        //已收藏，取消收藏
        await deleteCollect(this.articleId);
      } else {
        //未收藏，点击收藏
        await addCollect(this.articleId);
      }
      this.article.is_collected = !this.article.is_collected;
      // this.isCollectLoading = false
      this.$toast.success(`${this.article.is_collected ? "" : "取消"}收藏成功`);
    },
    //点赞、取消点赞
    async onLike() {
      this.$toast.loading({
        message: "操作中...",
        forbidClick: true, //禁止背景点击
      });
      if (this.article.attitude === 1) {
        //已点赞，取消点赞
        await deleteLike(this.articleId);
        this.article.attitude = -1;
      } else {
        //未点赞，点击点赞
        await addLike(this.articleId);
        this.article.attitude = 1;
      }
      this.$toast.success(
        `${this.article.attitude === 1 ? "" : "取消"}点赞成功`
      );
    },
    //发布评论或评论回复
    onPostSuccess(comment) {
      //把发布成功的评论数据对象放到评论列表顶部
      this.commentList.unshift(comment);
      //更新评论的总数量
      this.totalCommentCount++;
      //关闭发布评论弹出层
      this.isPostShow = false;
    },
    onReplyClick(comment) {
      this.replyComment = comment;

      //展示回复内容
      this.isReplyShow = true;
    },
  },
};
</script>

<style scoped lang='less'>
.article-wrap {
  position: fixed;
  left: 0;
  right: 0;
  top: 46px;
  bottom: 44px;
  overflow-y: auto;
}

.title {
  font-size: 20px;
  color: #3a3a3a;
  padding: 14px;
  background-color: #fff;
  margin: 0;
}

.user-info {
  .avatar {
    width: 35px;
    height: 35px;
    margin-right: 8px;
  }

  .name {
    font-size: 12px;
    color: #333333;
  }

  .pubdate {
    font-size: 11px;
    color: #b4b4b4;
  }

  .follow-btn {
    width: 85px;
    height: 29px;
  }
}

ul {
  list-style: unset;
}

.markdown-body {
  padding: 14px;
  background-color: #fff;
}

.article-bottom {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  justify-content: space-around;
  align-items: center;
  box-sizing: border-box;
  height: 44px;
  border-top: 1px solid #d8d8d8;
  background-color: #fff;

  .comment-btn {
    width: 141px;
    height: 23px;
    border: 1px solid #eeeeee;
    font-size: 15px;
    line-height: 23px;
    color: #a7a7a7;
  }

  .van-icon {
    font-size: 20px;

    .van-info {
      font-size: 11px;
      background-color: #e22829;
    }
  }
}
</style>